Rock drill



Feb. 4, 1941. A. J. THOWLESS ROCK DRILL Original Filed Aug. 25, 1933 2 Sheets-Sheet l INVENTOR I flrfiurjfiowless ATTORNEY Feb. 4, 1941. THOWLESS v 2,230,275

ROCK DRILL Original Filed Aug. 25, ,1933 2 Sheets-Sheet 2 INVENTOR Patented Feb. 4, 1941 UNITED STATES E ATENT OFFICE ROCK DRILL Arthur J. Thowless, Newark, N. J.

Original application August 25, 1933, Serial No. 686,677. Divided and this application July 17, 1937, Serial No. 154,117

Claims. (01. 25563) This invention relates to rock drills and more An object of this invention is to provide a particularly to a rock drill having means assodetachable drill stem and drill bit combination ciated therewith permitting attachment and dein which the shocks incident to drilling are transtachment of the bit. This application is a diviferred from the drill stem directly to the drill bit.

5 sion of my copending application Serial No. Another object of this invention is to provide 5 686,677, filed August 25, 1933, now Patent No. means which may be easily and quickly manipu- 2,089,230, issued August 10, 1937. lated by an unskilled operator to attach and de- Rock drills are subjected to considerable shock tach the drill bit and drill stem. I incident to the drilling operation. In rock drills Another object of this invention is to provide of the detachable drill bit type heretofore made, a detachable drill bit which is strong and durable 10 the shock from the drill bit is transferred inand which may be made at a minimum cost. directly to the drill shaft through the bit attach- Still another object of this invention is to proing device. For example, one type of detachable vide adjustable means for securely holding the bit now in use is provided with a threaded shank detachable drill bit to the drill stem which is which screws into a threaded sleeve connected to composed of few parts, inexpensive to manufac- 15 the drill stem. The shock incident to drilling is ture, which securely holds the bit in position thus transferred to the threaded parts of the bit during operation, and which may be easily and shank and sleeve with the result that the threads quickly manipulated by an unskilled operator become so hammered and worn that it is difficult when attachment or detachment of the drill bit to remove the bit or replace the bit onto the drill is desired. 20 stem. In addition to these defects, much of the Other objects of this invention will become working force desired to be transferred to the apparent as th di l sur proceed drill bit is lost effort and does not perform effec- In order that a cle r r understanding of my tive work. Detachable bits as heretofore made invention may be had, attention is hereby dihave been unduly complicated and expensive and reeted to the accompanying drawings, forming 25 have req d extensive machining d milling a part of this application and illustrating certain t0 manufacture them. The detaching devices possible embodiments of my invention, heretofore used are otherwise complicated, difli- Referring t th drawings; cult to manipul te a q y Wear 01115- Fig. 1 is a side view of my detachable bit and Dri l bits al o q c y Wear Out W en Operating drill stem combination, certain parts of the con- 30 on hard surfaces a d u t be replaced With a necting means being broken away to illustrate new bit. It is advantageous. therefore, p certain features of the construction;

vide a drill bllt which can be made as sturdy as Fig. 2 is a horizontal cross-sectional view possible and at aminimum of cost. through the drill bit and associated attaching In accordance with this invention, a drill stem means, t k on 1i 2-4 of Fig, 1; 35 and drill bit combination is p ov wherein the Fig. 3 is another side view of the drill bit and shocks incident to drilling are transferred directdrill t b ti shown i Fi 1, modified ly from the stem to the drill bit. The drill means being hown for detaching and connect.- bit is stro and sturdy in construction and can ing the drill bit to the drill stem;

b inexpensively made by a simple drop forging Fig. 4 is a side view of a further modification 40 op t The drill shank abuts t y a ns of the drill bit and drill stem and associated sethe broad end of the drill stem and is held therecuring devices; to by simple attaching devices which securely Fig. 5 is a horizontal cross-sectional view hold the drill bit to the drill Stem- The through the drill stem and securing devices shown meetin v e comprises one or m separable in Fig. 4, this view being taken on line 5 5 of 45 members provided with parts which engage and Fig 4;

interfit with corresponding locking parts provided Fig. 6 is a Side View of a modified form of on the drill stem and drill bit. The connecting a m t showing a modified form of drill t members are held in place y a Sleeve 01' r attaching means adapted for this type of conwhich telescopes over the member. The connectt ti n; 50 ing devices are not affected by the Shoc incl- Fig. 7 is a horizontal cross-sectional view dent to drilling and as a result may be made of through the drill stem and associated securing relatively light material. The drill bit may be means shown in Fig. 6, this view being taken easily and quickly attached and detached by an on line 1-1 of Fig. 6;

unskilled operator. Fig. 8 is a side view of a drill stem of the type 5 parts a of 'enlarged cross-section.

shown in Fig. 6 having drill bit-attaching means associated therewith of modified form;

Fig. 9 is another side view of the drill stem and associated drill bit shown in Fig. 8.

Fig. 10 is a side view of a drill stem and drill bit combination having a plurality of hinged members associated therewith for securing the drill bit to the drill stem;

Fig. 11 is a horizontal cross-sectional View through the drill bit and associated attaching devices shown in Fig. 10, this view being taken on line I lll of Fig. 10;

Fig. 12 is a side View of the drill stem and drill bit shown in Fig. 10 with the attaching devices removed;

Fig. 13 is a perspective view of one of the hinged members comprising the drill bit locking devices shown in Fig. 10;

Fig. 14 is a perspective view of the hinge shown in Fig. 10 which is attached to the drill stem and the locking member, as shown in Fig. 10; Fig, 15 shows a drill bit and drill stem combinationof polygonal cross-section having suitable securing devices associated therewith, the securingdevices being shown broken away and in cross-section to illustrate the construction;

Fig. 16 is a side View of the drill stem and drill bit combination with the attaching sleeve removed from its seating position; and

Fig, 17 is a horizontal cross-sectional view through the drill bit and associated securing de vices shown in Fig. 15, this view being taken on line l'|ll of Fig. 15.

Similar reference characters refer to similar parts throughout the several views of the specification and drawings. In the several embodiments'illustrat'ed herein, the several parts having generally similar and corresponding constructions and functions are indicated respectively by similar reference characters but with letter suffixes denoting the particular embodiments respectively.

There is shown in Figs. 1, 2 and 3, a rock drill stem A. and a detachable drill bit A. The drill stem A is reciprocated by suitable driving mechanism, well known in the art, so as to deliver hammer-like blows to the drill bit A. The drill stem A comprises a stem portion la having a drill head "3a. The drill bit A comprises a shank portion 8a of reduced cross-section and cutting It Will be noted that the end surface of the drill head to is substantially flat and abuts the flat adjacent surface ofthe shank portion 8a of the drill bit A. The drill 'stem A and the drill bit A are connected together by a pair of connecting members or-half portions Illa. The drill head 3a is provided with one or more horizontally extending slots 21a which receive corresponding projections (similar to the projections 29 shown in Fig. 2) extending from the half portions Illa and slots 38a which receive projections 30a. When the half portions [0a are applied and seatedwithin the corresponding recesses 27a provided in the drill head 3a and the corresponding recesses ZBa provided in the bit head 8a, the drill bit is securely held and locked to the drill stem la when the tubular sleeve [6a is applied. By referring more "often be replaced with fresh bits. Thesecuring devices as above described may be easily and "quickly manipulated by the unskilled'workman to permit ready detachment and attachment of the drill bit. The drill stem A delivers directly the successive impacts or blows to the head 8a of the drill bit as the drilling operation proceeds. It will be noted that the shocks or blows incident to drilling are delivered directly from the drill stem A to the drill bit A and substantially no strain or shock is placed upon the drill bit connecting device. Their only function is to support and hold the drill bit A in fixed abutment against the drill head 3a of the drill stem Ia.

There is shown in Fig. 1, means which may be employed for securing the sleeve lGa in operative position. In the form shown in Fig. 1 the drill stem I a is provided with a threaded portion 26a onto which the threads 25a provided on the collar [9a of the tubular sleeve 16a may be screwed. This is an inexpensive type of construction and in certain instances may find special recommendation.

In a similar manner, the devices illustrated in Figs. 4, 6 and 10 are provided with sleeves lfib, [60,1811 l 6] and 16g. respectively, having threads 25b, 25c, 25d, 25f and 25g on collars I91), I90, I911; if and l9g cooperating with threaded portions 262), 26c, 26d, 26f and 26g.

As a further modification there is shown in Fig. 3 a tubular sleeve l6b, the inner surface of which is provided with threads I301) which are adapted to screw over threads 311) provided on the 'outer surface of the half portions lllb. The remaining portions of this embodiment of the invention are similar to the corresponding portions of the form illustrated in Fig. 1, there being a drill'stem B having a stem portion l'b formed with "a drill head '3b and a drill bit B having a cutting portion 5b anda shank portion'8b. The drill head 3b is provided with slots 21b to receive projections 291) on half portions Nb and the shank portion 81) is provided with "slots -282) to receive projections 30b.

Under certain circumstances objection to the use 'of the separable half portions 10 may be raised on the ground that the parts can 'be dropped or lost during attachment or detachment of the driIl'bit. To overcome this objection a modified form of drill bit connecting "means, as shown in Figs. 4 and 5, maybe provided which comprises members 330 which are hinged at'th'e upper end thereof to the-collar portion "20 0f "the drill Stein -l0. Suitable formpf hihge'htlay be *pro'videdfor the -purpose,"as for example, 'a'leaf *hinge, one leafj lflc of which is secured to the connecting member 3:3'c andthe 'out'er leaf 'Mcto the shoulder portion "20. One or moremembers 330 may be provided, as "shown in "Fig. 5, which need extend only partiallyaround the circumferential area of the arm head 3'c 'andthe bit head 80. Where the hinge type of connection is used,"rounded projecting portions 34C and 3T0 extending from the members 330 are preferably provided to facilitate-entry intoth'e corresponding' sui'ikn recesses 35c and 8cprovided rspe'c- 'tively in the drill head "at "and the bit head tc. The tubular sleeve 16c telescopes'cver the'hi'nge'd members "330 as before andretains thesame in locked position with respect 1J0 the drill head "and drill stem.

If 'd'esiredjdrill bit connecting means maybe provided which comprises only one removable half portion lil'd,'a's shown in Fig-6. In this type of construction the-drill'h'eadBd is provided -'''with a downwardly pro'jetingflalnge 4 3 -'fo'rir'ied integlal 'th'rewithafld provided "with aflShOLildI' portion 44d which seats against-the'shoulder lid the drill head 3 and the bit head 8 or only parof the bit head 8d. The shoulder portion 44d of the flange 43d corresponds respectively to the shoulder portion ll of the half portion Md, The drill bit D is removed by unscrewing the threaded portion I 9d of the sleeve IBd, lifting the sleeve from its telescoping position over the half portion IUd, removing the half portion loci and lifting the drill head 8d of the drill bit D from its seating position within the retaining flange 43d. In this type of construction it is only necessary to manipulate one-half portion Hid to remove or replace the drill bit.

Fig. 8 shows a drill stem of the type shown in Fig. 6 but having associated therewith a hinged locking member 45a of the general type shown in Fig. 4. The hinged locking member 45a is connected to the shoulder portion 2e by means of a hinge, one leaf 40s of which is secured to the locking member 45c and the other leaf Me to the shoulder portion 2e. The locking member 45c may comprise a half portion as shown in Fig. 9 or less than a half portion as shown more particularly in Figs. 4 and 5. The locking member 45:; is provided with a shoulder portion 46c at the free end thereof which snugly fits around the neck portion 9e of the drill bit E.

As shown more particularly in Figs. 8 and 9, a modified form of tubular sleeve He may be provided which comprises a tubular band or ring which extends only partially over the associated drill bit connecting members. The ring member He may be provided with threads 48c which are adapted to screw over threads 4% provided on the outside surface of the connecting means comprising the locking member Me and the locking flange 43c.

A further modified form of drill bit connecting means is shown in Figs. 10 to 14 inclusive. There is here shown three connecting members 33 each provided with studs 5| j which fit within pickets 50f provided in the bit head 8 and studs or projections 53f which fit within pockets 52 provided in the drill head 3]. The connecting members 33] are attached to the drill head 3 by means of a hinge shown more particularly in Fig. 14. In order to permit the connecting members 33) to fit snugly around the bit head ti and the drill head 3 I prefer to provide a recess 54 in the drill head which receives the hinge leaf 4| 1 and a recess 55f on the inside face of the connecting member 33 which receives the hinge leaf 40 as shown more particularly in Fig. 10. Machine screws 58f or other suitable means are used to connect the hinge leaf 4|) to the drill head 31. The hinge leaf 40 is provided with an elongated slot 56 which receives a stud 51f projecting from the recess portion 55f of the connecting member 33 The stud 51f permanently holds the connecting member 33] in hinged position but the slot 561 permits Vertical adjustment or movement of the connecting member 33 with respect to the drill head 3f and the bit head 8. It is thus seen that this vertical adjustment of the connecting members 33f permits the stud portions 51 and 53f to lock themselves within the corresponding pockets 56 and 52 provided respectively on the bit head and the drill head. When thus attached the drill bit is held in proper connected position to the drill stem entirely through the agency of the projecting studs 5 If and 53f, leaving the hinge free from strain. The projecting studs 5lf and 531 are shaped so as to facilitate their entry into the corresponding pockets 56 and 52f provided respectively in the bit head and drill head. The connecting members 331 may completely surround tially surround the same in the manner shown more particularly in Fig. 11.

There is shown in Figs. 15, 16 and 1'7, a drill head 39 and bit head 8g of polygonal cross-section. The half portions lflg snugly fit around the polygonal drill head and bit head and accordingly are provided with flat sides 69g. This construction prevents possible turning of the drill bit, The drill head 39 and the bit head 89 may be provided with horizontal slots 65g and 66g respectively which receive corresponding projections 61g and 68g extending from the half portions IUg. The projections 61g and 689 further assist in preventing turning or rotating movement of the drill bit when in operative position.

The tubular sleeve lBg is provided with a plurality of trackways 129 within which the corners 13g and the edges My of the half portions Hlg slide. Thus the half portions l0g contact the inside surface of the tubular sleeve lBg at few points only. This type of construction is advantageous where the sleeve l6g is inclined to rust or stick to the half portions, making it difficult to remove the same. Since the sleeve contacts the half portions at few points only, the friction between these parts, which resists removal of the sleeve, is greatly reduced.

As a possible further modification, the tubular sleeve l6g may be held in telescoped position over the half portions lllg by means of a nut 109, shown more particularly in Fig. 15. The nut 109 seats over the sleeve I69 and is provided with threads Hg which engage threads 26g provided on the drill stem lg.

The various locking projections 29b and 361) shown in Fig. 3, projections 34c and 310 shown in Figs, 4 and 5, projections Md shown in Fig. 6, projections 5! and 53 shown in Figs. 10 and1'3, and projections 67g and 689 shown in Fig. 15, may be of any desired and convenient shape or form. It is further understood that these pro-jeotions may be formed either on the movable connecting devices as shown, or they may be formed directly on the bit shank and drill stem, in which case the corresponding receiving sockets would be formed on the movable connecting means.

Various modifications may be thus made both as to the shape and position of the locking projections and associated receiving pockets.

It is understood that the various parts and details above described and disclosed in the accompanying drawings may be used in various different combinations within the purview of this invention. By way of example only, there is shown in Figs. 1, 3, 8 and 15, different forms of tubular sleeves and associated means forlocking the sleeves in position. These various types of sleeves may be used interchangeably with the various types of drill stems, as shown in Figs. 1, 4, 6, 8, 10 and 16. Similarly, the various connecting devices, as shown in Figs. 1, 4, 6, 8, 10 and 16 may be used interchangeably and in combination with the different types of tubular sleeves and drill stems as above described. While detachable drill bit and drill stem combinations herein disclosed are all effective, practical and inexpensive to make, it will be understood that certain types herein shown may be more effective and more practical for certain conditions than others. In all the forms the drill bit may be inexpensively made by a simple drop forging operation, no machine work of any kind thereon being required. The drill stems, which is a permanent part of the drilling equipment, carries and supports the connecting mechanism which is a permanent part of the fixture. The shock incident to drilling is transferred directly from the drill stem to the drill bit, thus maximum efficiency is attained with a minimum of wear and .tear on the parts.

The connecting means herein disclosed may also be associated with rock automatic hammers and similar devices. Where the expression rock drill is herein used, therefore, it is understood to imply and encompass automatic hammers and similar devices.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. Rock drill apparatus including in combination, a drill stem and detachable one-piece drill bit connected therewith, said bit having an enlarged cutting portion and a reduced shank, said shank having a substantially flat surface arranged to abut the substantially flat surface provided at the end of said drill stem, means connecting said stem and shank including a hinged member fitting and overlapping the abutting ends of said stem and shank, and a cooperating projection and recess associated with said member and bit shank operative to detachably connect the same, and a single tubular sleeve telescoping over said member, said sleeve having a threaded connection for retaining it in a position wherein it is operative to retain the hinged member in stem and shank connecting position, the adjacent ends of said hinged member and said sleeve being spaced from said cutting portion so that blows delivered to said drill stem are imparted directly to the fiat end surface of the bit shank.

2. Rock drill apparatus including in combination, a drill stem and a detachable one-piece drill bit associated therewith, said bit having an enlarged cutting portion and a reduced shank, said shank having a substantially flat surface arranged to abut the substantially flat surface provided at the end of said drill stem, a flange extending from the end of said drill stem providing a fixed pocket for said bit shank, a detachable member connecting said stem and shank, said drill stem and said detachable member being shaped to permit turning of said shank thereon, and a tubular sleeve telescoping over said member to removably retain the same in stem and shank connecting position, the lower end of said.

flange and said sleeve being spaced from said cutting portion so that blows delivered to said drill stem are imparted directly to the flat end surface of the bit shank.

3. Rock drill apparatus including in combination, a drill stem and detachable one-piece drill bit associated therewith, said bit having an enlarged cutting portion and a reduced shank, said shank having a substantially flat solid end surface arranged to abut the substantially flat solid end surface of said drill stem, means detachably connecting said drill stem and bit shank, said connecting means including a connecting member fitting and overlapping the abutment ends of said drill stem and bit shank, and. a cooperating being spaced from said cutting portion so that Y the blows delivered to said drill stem are imparted entirely to the flat end surface of the bit shank.

4. Rock drill apparatus including in combination, a drill stem and detachable one-piece drill bit connected therewith, said bit having an enlarged cutting portion and a reduced shank,

,said shank having a substantially flat end surface arranged to abut the substantially fiat end surface of the end of said drill stem, means detachably connecting said stem and shank including a connecting member fitting and overlapping the abutting ends of said stem and shank, and a cooperating projection and recess associated with said member and bit shank, a tubular retaining sleeve telescoping over said connecting member operative to retain the same in stem and shank connecting position, and means attaching said connecting member to said drill stem for movement into and out of connecting position, said attaching means being operative to retain said connecting member in attachment with said drill stem when said retaining sleeve is removed from retaining position, and means for preventing removal of said retaining sleeve over the bit end of said drill stem, the lower end of said connecting member and said sleeve being spaced from said cutting portion so that blows delivered to said drill stem are imparted entirely to the flat end surface of the bit shank.

5. Rock drill apparatus including in combination, a drill stem and a detachable one-piece drill bit associated therewith, said bit having an enlarged cutting portion and a reduced shank, said shank having a substantially fiat surface arranged to abut the substantially fiat end surface of the end of said drill stem, a flange extending inwardly at the end of said drill stem providing a fixed pocket for said bit shank, said shank having a shoulder directly engaging said flange, a connecting member connecting said stem and shank, a tubular retaining sleeve telescoping over said connecting member to removably retain the same in stem and shank connecting position, and means attaching said connecting member to said drill stem for movement into and out of connecting position, said attaching means being operative to retain said connecting member in attachment with said drill stem when said retaining sleeve is removed from retaining position, the lower end of said flange and said sleeve being spaced from said cutting portion so that blows delivered to said drill stem are imparted entirely to the flat end surface of the bit shank.

ARTHUR J. THOWLESS. 

